google maps gunung salak - Google Maps
Although close to a major town (Bogor) you can see on this map that the 2 mountains (Salak and Pangrango) are very remote and rugged. I've been off roading in this area (the much smaller mountain gunung bunder to the north) and there's some very wild country out there.
There's a major air force helicopter base 30kms away , if they weren't flying this afternoon looking for the aircraft it says something about the weather around those mountains.
The map posted before showed the aircraft lost contact in the vicinity of Mt Pangrango , the bigger of the 2.